This invention is related to a control system for an implement of a work machine and, more specifically, to a control system that raises and lowers the implement automatically to facilitate the spreading or dissemination of loose material by the work machine.
It is common for a work machine such as a wheel loader to be fitted with a blade and used for material spreading tasks. In such an application, the operator of the work machine moves the blade to a higher or a lower position to aid in spreading out the material. More specifically, the operator will usually have the blade in a lower position when the work machine moves forward, in order to spread out the material from a pile. The operator will then raise the blade while or before moving the machine in reverse, so that the spread material is not dragged back toward its original position by the back side of the blade. The operator then drops the blade back down to the lower position to catch more material from the pile and the machine moves forward to push the additional material away from its original position. This type of spreading is commonly done in landfill or soil compaction applications.
It is obvious that the work cycle described above requires multiple motions from the operator (lowering and raising the blade and controlling the work machine in forward and reverse directions) which are accomplished through the manipulation of various levers, joysticks, or the like in the operator compartment. This myriad of motions for each work cycle can be fatiguing for the operator and lead to an inefficient work cycle as the operator tires.
U.S. Pat. No. 5,462,125, issued Oct. 31, 1995 to Ken L. Stratton et al. (hereafter referenced as xe2x80x2125) discloses a device and method for automatically moving the vehicle implement to one of several pre-set blade angle positions (col. 1, lines 7-9). The operator selects the automatic tilt mode by depressing the automatic tilt mode switch which sends an automatic tilt signal to the electronic control. The electronic control will thereafter issue a command to move the tilt cylinders to the pre-set blade angle corresponding to the given position of the thumb switch (col. 4, lines 20-26).
The xe2x80x2125 apparatus includes no provisions for allowing the operator to set raise and lower limit values, but merely allows the operator to choose from a group of preset tilt angle values. Therefore, the operator loses a portion of control over the precise placement of the implement. xe2x80x2125 also does not to allow the work machine to automatically engage the implement control system. Finally, xe2x80x2125 does not relate the implement control to a travel direction of the work machine, which would be advantageous in repeat-pass spreading.
Accordingly, the art has sought a method and apparatus of an implement control system that: reduces operator effort and fatigue, includes preselected and/or operator-chosen raise and lower limit values, relates implement control to a travel direction of the machine, and is economical to manufacture and use. The present invention is directed to solving one or more of the above problems.
In an embodiment of the present invention, a method for spreading material with a work machine is disclosed. The work machine has an operator input device, an implement, a ground-engaging device, and an implement position sensing system. The method includes the steps of: sensing a condition of the operator input device, responsively producing an operator input signal, sensing an implement position, and responsively producing an implement position signal. The method also includes the steps of: providing a programmable device for receiving the operator input signal and the implement position signal and responsively producing and outputting an implement position command, receiving the implement position command, and responsively controlling a position of the implement.
In an embodiment of the present invention, an automatic implement control system for a work machine is disclosed. The automatic implement control system includes: a work implement attached to the work machine, an implement sensor adapted to sense a work implement position and responsively produce an implement position signal, an operator input device assembly adapted to sense an operator command and responsively produce an operator input signal, and an electronic control module adapted to receive the implement position signal and operator command signal and responsively produce a work implement command signal to control the work implement to a predetermined position.
In an embodiment of the present invention, a method of controlling the position of a work implement is disclosed. The method includes the steps of: determining a raise limit, determining a lower limit, sensing an operator command and responsively producing an operator input signal, sensing a work implement position and responsively producing an implement position signal, and sensing a machine direction and responsively producing a machine direction signal. The method also includes the steps of: providing a programmable device for receiving the operator command signal, the implement position signal, and the machine direction signal; responsively producing an implement command signal; moving the work implement toward the raise limit when the transmission signal has a value of reverse; and moving the work implement toward the lower limit when the transmission signal has a value of forward.
In an embodiment of the present invention, a method of controlling the position of a work implement is disclosed. The method includes the steps of: predetermining a raise limit, predetermining a lower limit, sensing a position of an operator input device and responsively producing an operator input signal, and sensing a work implement position and responsively producing an implement position signal. The method also includes the steps of: providing a programmable device for receiving the operator input signal and the implement position signal, responsively producing an implement command signal, moving the work implement toward the raise limit when the operator input signal has a first predetermined value, and moving the work implement toward the lower limit when the operator input signal has a second predetermined value.
In an embodiment of the present invention, a method for spreading material with a work machine is disclosed. The work machine has an operator input device, an implement, a ground-engaging device, and an implement position sensing system. The method includes the steps of: sensing a condition of the operator input device, responsively producing an operator input signal, sensing an implement position, responsively producing an implement position signal, sensing at least one of a machine travel direction condition and a detent position of the operator input device, and responsively producing at least one of a machine direction signal and a detent signal. The method also includes the steps of: receiving at least two of the operator input signal, the implement position signal, the machine direction signal, and the detent signal, and responsively producing an implement position command; receiving the implement position command; and responsively controlling a position of the implement.